Studying and modeling the effects of quartz addition and heat treatment on mechanical properties of glass-ceramic coating

Abstract EN

In this work, a new glass-ceramic coating has been developed and applied, as a single coat without prior chemical treatment of the surface, using the dipping technique on metal substrate.

the coating are designed for application on varies grades of low alloy steel, the selected substrate was low carbon low alloyed steel with (0.2)%C.

Various heat treatments at temperatures ( 500,550, and 600˚C ) at different times (60 & 120)min and with quartz addition in the range (0-15)% were used to obtain a glass-ceramics that have the optimum coating properties.

These coating have been characterized by x-ray diffraction analyses and the results showed presence of a number of microcrystalline phases which are formed during the heat treatments.

The results showed the suitability of this coating for protection the metal substrate which was used in present work.

The results of tests also indicated that the mechanical properties ( hardness, adhesion strength, and thermal stability) of resultant coating were greatly improved by both addition of quartz into enamel frit and heat treatments for all cases, this is attributed to the formation of complex network from crystalline phases(Li2SiO3, Li2TiSiO5, NaAlSi2O6, and SiO2) which are the main phases in the resultant glass-ceramic coating.

It has been found that the heat treatment at 600˚C for 120min with 15% quartz addition brought the optimum values for ( hardness, adhesion strength, and thermal stability) of resultant coating which are improved by (70.58%, 33.84%, and 39.68%) respectively.

Mathematical modeling is implemented and regression equations are obtained using ( SPSS ) software to predict the experimental data for mechanical properties of resultant coating.

Comparing the predicted and measured values gives high prediction accuracy.

The accuracy of prediction has been (98%, 98.5%, and 97.4%) for ( hardness, adhesion strength, and thermal stability) respectively.